This invention is directed to a support assembly for an outside mirror on a motor vehicle, especially for a commercial vehicle, and concerns additionally an outside mirror with such a support assembly.
External, rear view mirrors for motor vehicles in accord with the state of the technology have at least one mirror head, which contains at least one mirror pane. Mirror panes of this kind can be placed rigidly or adjustably in a housing or can be directly affixed within a peripheral rim. Under certain circumstances the mirror housing can have an integral, motor operated adjustment for automatic angular positioning of the mirror pane in relation to the vertical and horizontal axes of the housing. Additionally, the external mirror may also possess heating elements for the warming of the mirror or be fitted with the like.
In one simple variant, a mirror head is fastened by a U-shaped, tubular metallic yoke having two end fixtures which fit into abutments on the vehicle. In EP 0 090 909 A3 for example, the adjustments are preset by means of clamp connections on the yoke. Conversely, EP 0 590 510 B1 teaches that clamping on the housing itself can adjustably secure the mirror head. The tubular yoke, with its own connections, can be fastened onto abutments on the vehicle with pivotal end fittings and allow angular adjustment. For this purpose, EP 0 697 311 B1 proposes the fastening of plastic bearing blocks onto the metallic, tubular yoke, whereby a frictionally restrained movement of the yoke in angular directions is possible.
Although the above designs are very stable and simple, they present a series of disadvantages. For instance, the mirror pane (when held by the housing or the adjustment device) is only restrained from unwanted turning by frictional resistance. The construction is not of the best aerodynamic design. This disadvantage increases the danger of displacement during high wind exposure. To prevent this, the yoke, when built for structural strength, disadvantageously becomes very heavy. In addition, the furnishing of additional plastic anchor bolting brings about an unwanted plurality of individual parts. This increases the cost of the manufacture of the mirror assembly and also increases expense for mounting.
EP 1 024 0541 A2 proposes, in this matter, a one-piece supporting structure which branches into two support arms each with its own mounting means. Onto the mounting means of the support arms, which are plastic in composition, a carrier plate for the mirror housing can be fastened by means of complementary joining devices. Similarly, EP 1 013 502 A1 offers a rear view mirror arrangement with a bearing body of plastic for the retention of a mirror pane, this bearing body is made in one part and includes two hollow support arms.
Also, these modes of construction lead to a multiplicity of disadvantages namely, first, the mirror housings, which have been conceived for the above mentioned tubular yoke versions, are not affixed to a support arm. In this case it becomes necessary to continually require a plurality of housing auxiliary parts. Further, it is possible that the known housing having tubular yoke supports cannot be improved by upgrading to achieve an aerodynamically more favorable design with less air resistance. Nor is it possible with such a support arm to enclose a mirror pane within a rim or a housing.
Moreover, the structural strength of the support arm, which is made completely of plastic, is so limited that a mirror affixed to a vehicle can be exceedingly damaged by vibrations due to wind or by vibrations emanating from the vehicle itself. In order to improve the limited structural strength of a totally plastic mirror supporting device, EP 1 531 084 B1 proposes to at least construct the mirror head out of metal.
For the fastening of a mirror head onto its assigned brace according to EP 1 531 084 B1, a specially designed attachment is required. In the above described tubular yoke versions, the same support arm can be used for right and left driven vehicles and the support arm is easily adapted to such a change by a simple reversal of parts. However, the attachment EP 1 531 084 B1 is of such a nature that it becomes impossible to use an identical support arm for installations on the right and left sides of a vehicle. Looking in the direction of travel, the left outside mirror, in the case of left driven vehicles, is the driver's mirror. On this account the mirror requires little angular adjustment. Conversely, in the case of right driven vehicles, this arrangement is exactly reversed. Therefore, it becomes necessary, up to this time, to continually make available four variants. These variants are, for example, driver and passenger mirrors for right driven vehicles, and driver and passenger mirrors for left driven vehicles. To this end, DE 295 04 245 U1 teaches between the mirror base and the mirror housing an additional adapter part may be installed, which affixes the housing opposite to its base at various selected angles. This now added part or parts increases not only the weight, manufacturing time, and mounting labor, but also introduces additional sources of vibration.
Because of challenges to design, mirror supporting devices can no longer be made as tubular yokes, but must now possess a shape as is disclosed by EP 1 531 084 A1. In the case of the mirror supporting devices made known by EP 1 531 084 A1, a mirror head brace is to be made of metal tubing. So that the mirror head will be mounted in the same position and angular setting as the therein contained mirror, a requirement is that fastening devices, or at least indicative markings, be placed on these metal tube elements. That is to say, for each external mirror variant, and for the left and right external mirror, different metal tube braces must be manufactured and kept in inventory. The direct costs of manufacture of various metal tubes when compared to a variant are possibly not greater, but the storage and logistic costs become excessive. Alternatively, the mirror head can be always bound in the same manner to its mirror head brace and the different angular settings be achieved by different fastenings of the mirror head onto the upper and lower support arms. This leads to a considerably high construction cost and the danger of an erroneous assembly of the parts.
Basing design on EP 1 531 084 A1, the purpose of the present invention is to create a support assembly for outside mirrors on a motor vehicle, which assures a simple mounting of mirror heads in preselected angular positions. Further, it is the purpose of the present invention to make available a left or a right external mirror for a motor vehicle with such a support assembly.